Labour & Employment Law Blog

Workplace Safety and the Extent of a Due Diligence Defence

Zeilikman Law

Zeilikman Law

Case Summary

Employees in Ontario have the right to work in conditions that are safe. Workplaces covered by the WSIB (and they are many) allow employees to claim benefits in the event of a work related injury. As a result of WSIB coverage, the employee would not be allowed to sue the employer for damages related to a workplace injury and the compliant employer’s risk of financial exposure would be limited to the payment of premiums only.

However, employers may also be subject to prosecution under the Occupational Health and Safety Act R.S.O. 1990, c. O.1 (the “Act“) if there are allegations that an employer has allowed its employee to work in unsafe workplaces. If charged under the Act, employers may be subject to severe penalties. In such cases, one of the employer’s options is to use the defence of due diligence to counter any claims of liability. For example, the employer may argue that they took all reasonable steps to prevent hazards or accidents in its workplace.

A recent Ontario decision has confirmed that an employer can invoke a due diligence defence to counter claims of liability. However, a strong caveat to the above is that a due diligence defence may be difficult for the employer to establish.


R. v. ABS Machining Inc., 2015 ONCJ 213 (CanLII) was a case that centered on an incident that took place which resulted in a serious injury to an employee. ABS Machining Inc. (“ABS”), a metal manufacturing company, had a deal with another company, Caterpillar Inc. (“Caterpillar”), for the production of six rear spindles. These spindles are large cylindrical components for Caterpillar’s massive trucks used in the oil industry. Whilst completing the second spindle, Caterpillar issued orders for modification of the spindles – the “tunnel” of each spindle needed to be wider.

ABS implemented the required changes starting from the next spindle on the production line; the existing one was to be modified by hand. An employee of ABS, Michael Antoni (“Antoni”) a deburrer, and his supervisor Ian Sue (“Sue”) were charged with the aforementioned task.

The spindle was initially facing the incorrect direction, and Sue noted that it needed to be rotated prior to the commencement of their work. While waiting to sign out the tools required for the job, Antoni contends that Sue instructed him to “prep and rotate” the spindle. Antoni proceeded to do so using an unconventional method not commonly employed for such heavy materials. Whilst raised, the spindle came crashing down on Antoni’s right foot, which had to be amputated thereafter.

The Ontario Ministry of Labour charged ABS on two fronts under the Act – 1) failing to ensure “that the spindle was lifted and/or carried and/or moved in such a way and/or with such precautions and/or safeguards that did not endanger the safety of the worker as per” and 2) failing “to provide information and/or instruction and/or supervision to a worker regarding how to safely move the spindle.”

The charges laid in contravention of section 45(a) of Ontario Regulation 851, R.R.O 1990, as amended, and section 25(2)(a) of the Act, as amended, are strict liability offences. This means that initially the burden lies with the prosecution to prove beyond a reasonable doubt that the infringing/guilty act occurred. Once proven, the burden shifts to the accused who’s given an opportunity to raise a defence of due diligence.


ABS claimed that the “act” cannot be proven because Antoni was not in a position to require any instruction on how to lift the spindle in the first place, let alone the actual ensuring that it is moved with the proper precautions. The reason that ABS took this stance is that Antoni was inexperienced and had never been responsible for such tasks despite receiving some analogous training. Furthermore, they relied upon Zisman J. in Ontario (Ministry of Labour) v. 679052 Ontario Ltd. (c.o.b. Auction Reconditioning Centre), [2012] O.J. no. 5849 (Ont. Court of Justice) in asserting their claim. Zisman J. held that a company was not responsible for instructing or ensuring the safety of an employee responsible for cleaning cars who then chose to drive a customer’s car on their own accord. However, the Court distinguished the case in that the employee’s job had no involvement with driving, and the employee in question did not even have a driver’s license. The Court thus made clear that despite it not being part of Antoni’s responsibility to move large, heavy, pieces, Antoni’s job did in fact involve moving smaller products and pieces, and as such the accused’s case was not analogous.

The Court invoked a broad, liberal, meaning when consulting the Act, “to satisfy [its] intended role in safeguarding a minimum level of protection for the health and safety of workers.” From the Court’s analysis it was made apparent that ABS did indeed have a responsibility to both instruct Antoni as well as ensure that the proper measures and precautions were being followed with respect to Antoni’s actions with the spindle.

With the guilty act established, the Court turned to assess the due diligence defence put forward by ABS. At trial Antoni conceded that he did not adhere to all of the tenets of his training program, and revealed that the moving technique he employed was in fact taught to him by a fellow deburrer, not a superior, and involved far lighter and smaller pieces than the spindle.

R. v. Sault Ste. Marie (City)1978 CanLII 11 (SCC), [1978] 2 S.C.R. 1299 set out that the due diligence defence is to consist of proof “that every precaution reasonable in the circumstances was taken.”

The Court referred to R. v. Stelco Inc.  2006 CanLII 28110 (ON SC), [2006] O.J. No. 3332 (Ont. S.C.) to further clarify the defence of due diligence. The Court was concerned with the balance of precautions that are to be taken, how far does an employer’s duty extend? R. v. Stelco Inc. answered this question by explaining that “[t]here will always be the possibility that an employee could circumvent whatever safety device is in place…the objectives of the Act can be met by making that circumvention as difficult as can be reasonably possible.” Thus an employer’s duty, within the scope of the due diligence defence, is not to guard against every possible occurrence/circumvention of safety but rather to ensure, to a reasonable degree, that the employees are afforded the most protection possible in a given situation and that, also to a reasonable degree, circumvention is made as difficult as possible.

The Court thus made clear that relying upon Antoni’s negligence and improper conduct alone would not be enough to form a proper a defence of due diligence. The issue, the Court highlighted, was whether the occurrence was reasonably foreseeable such that ABS was prepared for such potential circumvention of its safety protocols.

The Court ruled that on the balance of probabilities there was no reason to believe that Sue directly instructed Antoni to rotate the spindle. Nor was there any reason to believe that there had been a misunderstanding. The Court thus stressed that the issue alone remains whether the circumvention of safety protocols was a reasonably foreseeable occurrence.

The Court concluded that the occurrence could not have been reasonably foreseeable, because (1) there was previously no evidence of low-ranked employees moving large/heavy objects, (2) there was a protocol in place ensuring that no low-ranked employee move large/heavy objects without supervision, (3) Antoni’s method of rotation was contrary to his training, and (4) never had an employee of Antoni’s position moved any large, heavy or new objects on their own without supervision.

However, although established as not reasonably foreseeable, the Crown contended that ABS still did not employ every precaution reasonable in these circumstances. The Crown asserted that ABS should have made clear to Antoni not to rotate the spindle, accompanied and instructed Antoni all the time, fenced off the spindle, and designed a stand for spindle.

In assessing the Crown’s argument the Court looked to Canada (Fisheries and Oceans) v. Ontario (Ministry of Transportation), [2014] O.J. No 5986 (Ont. S.C.) for five factors crucial to assessing a defence of due diligence: (1) the gravity of potential harm, (2) the likelihood of harm, (3) the degree of knowledge or skill expected of the accused, (4) the alternatives available to the accused, and (5) the extent the accused could control the causal elements in the offence.

The Court explained that although the gravity of the harm is obvious, the likelihood of the harm is not high because the occurrence was not reasonably foreseeable. The alternatives available, that is to monitor Antoni and advise him on each task, is a categorically unreasonable expectation.

The Court held that ABS had taken all reasonable precautions in appreciating potential hazards, however the occurrence in the case at hand was an unforeseeable one and the Court was reluctant to agree with the Crown that there was something further that ABS could have done. Thus, the Court ruled in favour of ABS and accepted their defence of due diligence.


Cases involving workplace injuries have many intricacies and balancing acts. It is crucial to understand what your position entails and what tasks you may undertake by yourself. It is doubly crucial to be clear with your supervisors and ensure that they make it adamantly clear whether a certain task is within your purview or not. It is far more beneficial to air on the side of caution and not work ahead without clear instructions because a resulting injury may then be completely upon your own shoulders.

If you are an employer, it is important for you to be clear with your employees about their duties. It is also integral to consistently and obsessively go through safety protocols and precautions, making sure that all your employees are properly trained in safety practices. The key rationale that employers should keep in mind when it comes to safety is that they are not responsible for stopping every possible unsafe situation/circumvention of safety protocols, but rather, they are responsible for ensuring that any such occurrence or circumvention is made as unlikely as reasonably possible.

The above article is for general information purposes only, does not constitute legal advice or create a solicitor-client relationship. Because each case is unique and factually driven, if you have concerns with regard to the foregoing issues, please make an appointment with one of our lawyers or a qualified legal practitioner elsewhere. We represent clients in the Greater Toronto Area including Toronto, North York, Markham, Vaughan, Thornhill, Newmarket, Aurora, Brampton, Mississauga, Barrie, Ajax, Whitby, Pickering and Oshawa.